Method of combating insect eggs

ABSTRACT

A method of destroying insect eggs and a method of protecting crops from the insects resulting from the eggs wherein a compound of formula (I) is applied to the eggs

This application claims priority of copending U.S. provisional patentapplication Ser. No. 60/058,445, filed Sep. 10, 1997, incorporated byreference herein in its entirety and relied upon.

This nvention relates to a new method of combating imcrt at the egglevel of development at a locus at which there is a growing crop,especially a plantation crop. The invention is also directed to a methodof protecting crops.

Many insecticides are well known as active ingredients to protect plantsagainst insects. However the compounds which are recommended purely fortheir ovicidal action are rather rare, and those which have both aninsecticidal and an ovicidal action are also rather rare. It isgenerally accepted that in the art of insecticides for cotton, plantswhich have a gene incorporated in them which encodes for Bacillusthuringiensis delta-endotoxin expression are not effective against eggs.Thus there exists a need for new insect ovicides. From the activity of acompound on insects (adults or larvae), nothing can be deduced regardingthe activity on eggs. Fo9r example, insecticides such as carbaryl orphosphate insecticides are not ovicidal. Pyrethroids are not ovicidaleither; if they have been sometimes considered as ovicidal, it is justbecause they are able to kill the larvae when going out from the eggs,but this is not a true ovicidal action. Thiodicarb is considered ashaving both an ovicidal and an insecticidal action, but it is rather anexception.

An object of the present invention is to provide a new method for insectegg control. Another object of the present invention is to provide a newmethod of protecting crops. These objects are met in whole or in part bythe present invention.

The present invention provides a meythod of destroying eggs of insectswhereby a compound of formula (T): ##STR1## wherein: R₁ is CN or methylor a halogen atom;

R₂ is S(O)_(n) R₃ or 4,5-dicyanoimidazol 2-yl or haloalkyl;

R₃ is alkyl or haloalkyl;

R₄ is selected from the group consisting of hydrogen, halogen, --NR₅ R₆,--C(O)OR₇, --S(O)_(m) R₇, alkyl, haloalkyl, --OR₈, --N═C(R₉)(R₁₀) and--C(O)alkyl;

R₅ and R₆ are independently selected from a hydrogen atom, alkyl,haloalkyl, --C(O)alkyl, --C(O)OR₇, --S(O)_(r) CF₃ ; or R₅ and R₆ formtogether a divalent alkylene radical which may be interrupted by one ormore heteroatoms, preferably selected from oxygen, nitrogen and sulfur;

R₇ is selected from alkyl and haloalkyl;

R₈ is selected from alkyl, haloalkyl and hydrogen;

R₉ is selected from hydrogen and alkyl;

R₁₀ is selected from phenyl or heteroaryl each of which is unsubstitutedor substituted by one or more hydroxy, halogen, --O-alkyl, --S-alkyl,cyano, or alkyl or combinations thereof;

X is selected from nitrogen and --C--R₁₂ ;

R₁₁ and R₁₂ are independently selected from halogen or hydrogen or CN orNO₂ ;

R₁₃ is selected from halogen, haloalkyl, haloalkoxy, --S(O)_(q) CF₃,--SF₅ ; m, n, q, r are independently selected 0, 1, and 2; provided thatwhen R₁ is methyl, R₃ is haloalkyl, R₄ is NH₂, R₁₁ is Cl, R₁₃ is CF₃,and X is N and provided that when R₂ is 4,5-dicyanoimidazol 2-yl, R₄ isCl, R₁₁ is Cl, R₁₃ is CF₃, and X is ═C-Cl; or a pesticidally acceptablesalt thereof is applied on the eggs.

The alkyl and alkoxy groups and moleties thereof of the formula (I) arepreferabloy lower alkyl and alkoxy groups, that is, groups having one tosix carbon atoms. The haloalkyl and haloalkoxy groups likewisepreferably have one to four carbon atoms. The haloalkyl and haloalkoxygro0ups can bear one or more halogen atoms; preferred groups of thistype include --CF₃ and --OCF₃. It shall be understood that the ringformed by the divalent alkylene radical represented by R₅ and R₆ andincluding the nitrogen atom to which R₅ and R₆ are attached is generallya 5, 6, or 7-membered ring. When R₁₀ is heteroaryl, it is preferablypyridyl, most preferably 2-pyridyl. It will be understood that the1-arylpyrazoles of formula (I) include enantiomers and/or diastereomersthereof.

A preferred group of 1-arylpyrazoles for use in the present inventionare those of formula (I) with one or more of the following featureswherein:

R₁ is CN;

R₄ is --NR₅ R₆ ;

R₅ and R₆ are independently selected from the hydrogen atom, alkyl,haloalkyl, C(O)alkyl, C(O)OR₇ ;

X is C--R₁₂ ; or

R₁₃ is selected from a halogen atom, haloalkyl, haloalkoxy, and --SF₅.

Another preferred group of 1-arylpyrazoles of formula (I) for use in thepresent invention is that wherein:

R₁ is CN;

R₃ is a haloalkyl radical;

R₄ is NH₂ ;

X is C--R₁₂ ;

R₁₁ and R₁₂ represent, independently of one another, a halogen atom; and

R₁₃ is a haloalkyl radical.

A most preferred compound is 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinyl-3-cyanopyrazole, hereafter designatedas compound (A). Another highly preferred compound according to thepresent invention is 5-amino1-(2,6-dichloro-4-trifluoromethylphenyl)-4-ehtylsulfinyl-3-cyanopyrazole,hereafter designated as compound (B).

Compounds of formula (I) and compositions containing them may beprepared according to known processes, for example as described inInternational Patent Publications WO 87/3781, 93/6089, and 94/21606 aswell as in European Patent Applications 295117, 403300, 385809 or679650, German Patent Publication 19511269 and U.S. Pat. Nos. 5232940and 5236938 or other process according to the knowledge of a man skilledin the art of chemical synthesis, which is deemed to incloude theChemical Abstract and the literature referred to therein. Compositionscomprising the compounds of formula (I) may also be prepared accordingto the teaching of same prior art or similar one.

The present invention also provides a method of protecting a crop bycombating eggs of insects susceptible to damage the said crop whereby aneffective amount of a compound of formula (I), or a pesticidallyacceptable salt thereof, is applied at a crop locus where there areeggs.

The crops that may be protected by the means of the present inventioninclude cotton, rice, corn and vegetable crops.

The insect eggs that generally controlled or destroyed by the means ofthe present invention include those of Heliothis spp., preferablyHeliothis zea, and rice leaffolders and rice stemborers, preferablyChilo suppressalis and Tryporyza incetulas.

By the term "eggs" as used in this specification, it is to be understoodeggs which are in their simple state laid upon the soil or on the plantor eggs which are inside a pregnant insect. Most of the eggs which areto be killed according to the present invention are eggs upon leaves, sothat the method whereby a compound of formula (I), or a pesticidallyacceptable salt thereof, is applied is also a treatment of leaves ofcrops.

The compounds of the invention may be applied once, or more than once.Thus, for some crops one may apply the ovicidal compounds periodicallythrough the growing season. Usually ovicidal compositions according tothe invention are applied to the crop area at a rate of 0.04 to 2 kg/haof active ingredient, preferably 0.1 to 1 kg/ha.

Ovicidal compositions according to the invention may be applied in amanner which is safe for the crop.

The ovicidal concentrated compositions according to the invention may bein the form of a solid, e.g. dusts or granules or wettable powders, or,preferably, in the form of a liquid, such as an emulsifiable concentrateor a true solution. The concentrated compositions are the compositionswhich are commercialized or transported or stored. For application toplant they are normally diluted in water and applied in such a dilutedform. The diluted form are part of the invention as well as theconcentrated forms.

The concentrated ovicidal compositions of the inventions containgenerally form 0.001 to 90% of active ingredient of formula (I), or asalt thereof. A concentrate may contain from 5 to 90% of activeingredient. Parts and percentages in this specification are by weightunless otherwise indicated.

The ovicidal compositions may also contain all kind of compatiblesurface active agent and/or carrier. The agriculturally acceptablecarrier may be solid or liquid. The composition may further contain afertilizer.

The compounds of formula (I), or a salt thereof, may be used in sequenceor admixture, particularly admixtures with another pesticide e.g. aninsecticide, acaricide or fungicide.

The ovicidal compositions may be prepared by admixing the ingredients.

The invention is illustrated by the following test examples.

EXAMPLE 1

Cotton bollworm (Heliothis zea) eggs were placed on cotton leaves of agrowing cotton plant. Compound (A) as a 2.5% emulsifiable concentrate(as the product REGENT®) was applied to the leaves at rates ob 0.37 and0.037 kg/Ha. The leaves infested with eggs were removed from the plant,placed in petri dishes on water moistened paper. After three days, atboth rates, all eggs were dead.

EXAMPLE 2

Example 1 was repeated using Compound (B) at rates of 0.37 and 0.11kg/Ha. After three days, at 0.37 kg/Ha, about 59% of the eggs were dead.After three days, at 0.11 kg/Ha, about 23% of the eggs were dead.

EXAMPLE 3

Compound (A) as a 50% suspended concentrate formulation (as in ASCEND®)was applied at 25 g/Ha as a leaf dip to freshly cut rice leaves whichhad on them the eggs of Yellow stemborer Tryporyza incertulas) andStriped stemborer (Chilo suppressalis). The leaves were kept moist intest tubes for 7 to 9 days. Five replicates were made. For Stripedstemborer, an averge of 30% of the eggs did not hatch versus a controlexperiment. For Yellow stemborer, an average of 2% of the eggs did notbatch versus a control experiment.

EXAMPLE 4

Adults of Striped stemborer and Rice Leaffolder were allowed to ovipositon rice leaves petri dishes. Compound (A) as a 50% suspended concentrateformulation (as in ASCEND®) was applied to the eggs of Striped stemborerand Rice Leaffolder in petri dishes at rates of 25 g/Ha, 37.5 g/Ha and50 g/Ha. Five replicates were performed. After about 6 days thefollowing averaged results were observed:

    ______________________________________                                        Rate of Compound (A) g/Ha                                                                       % Non Hatched Eggs                                          ______________________________________                                        Rice Leaffolder                                                               25                51                                                            37.5            61.5                                                        50                71                                                          Striped Stemborer                                                             25                7                                                             37.5            47                                                          50                67                                                          ______________________________________                                    

What is claimed is:
 1. A method destroying eggs of insects whereby acompound of formula (I): ##STR2## wherein: R₁ is CN or methyl or ahalogen atom;R₂ is S(O)_(n) R₃ or 4,5-dicyanoimidazol 2-yl or haloalkyl;R₃ is alkyl or haloalkyl; R₄ is selected from the group consisting ofhydrogen, halogen, --NR₅ R₆, --C(O)OR₇, --S(O)_(m) R₇, alkyl, haloalkyl,--OR₈, --N═C(R₉)(R₁₀) and --C(O)alkyl; R₅ and R₆ are independentlyselected from a hydrogen atom, alkyl, haloalkyl, --C(O)alkyl, --C(O)OR₇,--S(O)_(r) CF₃ ; or R₅ and R₆ form together a divalent alkylene radicalwhich may be interrupted by one or more heteroatoms. preferably selectedfrom oxcygen, nitrogen and sulfur; R₇ is selected from alkyl andhaloalkyl; R₈ is selected from alkyl, haloalkyl and hydrogen; R₉ isselected from hydrogen and alkyl; R₁₀ is selected from phenyl orheteroaryl each of which is unsubstituted or substituted by one or morehydroxy, halogen, --O-alkyl, --S-alkyl, cyano, or alkyl or combinationsthereof; X is selected from nitrogen and --C--R₁₂ ; R₁₁ and R₁₂ areindependently selected from halogen hydrogen or CN or NO₂ ; R₁₃ isselected from halogen, haloalkyl, haloalkoxy, --S(O)_(q) CF₃, --SF₅ ; m,n, q, r are independently selected from 0, 1, and 2; provided that whenR₁ is methyl, R₃ is haloalkyl, R₄ is NH₂, R₁₁ is Cl, R₁₃ is CFR₃, and Xis N and provided that when R₂ is 4,5-dicyanoimidazxol 2-yl, R₄ is Cl,R₁₁ is Cl, R₁₃ is CF₃, and X is ═C-Cl; or a pesticidally acceptable saltthereof is applkied on the eggs.
 2. A methodd according to claim 1wherein the compound of formula (I) has one or more of the followingfeatures:R₁ is CN; R₄ is --NR₅ R₆ ; R₅ R₆ are independently selectedfrom the hydrogen atom, alkyl, haloalkyl, C(O)alkyl, C(O)OR₇ ; X isC--R₁₂ ; or R₁₃ is selected from a halogen atom, haloalkyl, haloalkoxy,and --SF₅.
 3. A method according to claim 1 wherein the compund offormula (I) is one wherein:R₁ is CN; R₃ is a haloalkyl radical; R₄ isNH₂ ; X is C--R₁₂ ; R₁₁ and R₁₂ represent, independently of one another,a halogen atom; and R₁₃ is a haloalkyl radical.
 4. A method according toclaim 1 wherein the compound of formula (I) is5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinyl-3-cyanopyrazole or 5-amino1(2,6-dichloro-4-trifluoromethylphenyl)-4-ethylsulfinyl-3-cyanopyrazole.5. A method of protecting a crop by combating eggs of insectssusceptible to damage the said crop whereby an effective amount of acompound of formula (I) as defined in claim 1, or a pesticidallyacceptable salt thereof, is applied at a crop locus where there areeggs.
 6. A method according to claim 5 wherein the crop is cotton, rice,corn or vegetables.
 7. A method according to claim 5 wherein thecompound of formula (I) is applied from 0.01 to 2 kg/Ha.
 8. A methodaccordinbg to claim 1 wherein the eggs are those of Heliothis xzea,Chilo suppressalis, Tryporyza incertulas or Rice Leaffolder.